Busy Philipps is pregnant

Busy Philipps attends theBaby2Baby Gala at The BookBindery on Nov. 3, 2012, in Culver City, Calif.

Busy Philipps is expecting a second baby. The 33-year-old actress revealed the news on Twitter, by posting a picture of her positive pregnancy test, with the tweet: "So this happened..."

Philipps and her husband, Marc Silverstein, are already parents to 4-year-old daughter, Birdie Leigh.

"I only became a celebrity because I had a kid. Before I was pregnant nobody cared," Philipps has joked, reports People. "I joke to my agent that having a baby made my career."

Philips has starred in "Dawson's Creek" and "Cougar Town." She recently made a guest appearance on "Don't Trust the B.... in Apartment 23" and is also attached to the upcoming romantic comedy, "A Case of You," co-starring co-stars Peter Dinklage, Vince Vaughn, Evan Rachel Wood and Justin Long.